Irritable Bowel Syndrome (IBS): This condition is characterized by recurrent abdominal pain associated with a change in bowel habits, such as diarrhea or constipation, without any visible signs of damage or disease in the digestive tract. The symptoms described, including frequent bowel movements, urgency after eating, and general abdominal discomfort without blood in the stool, align closely with IBS, particularly the diarrhea-predominant subtype (IBS-D).

Infectious Gastroenteritis: Although the duration of symptoms is somewhat prolonged for typical viral gastroenteritis, certain bacterial or parasitic infections can cause prolonged diarrhea. The absence of blood and the description of wet, small amounts of stool could still fit with an infectious cause, especially if the infection is not fully cleared or if there's a persistent infection.
Inflammatory Bowel Disease (IBD): Conditions like Crohn's disease and ulcerative colitis can present with chronic diarrhea, abdominal pain, and urgency. However, the absence of blood in the stool and the lack of weight loss or other systemic symptoms make this less likely but still a consideration.
Food Intolerance or Sensitivity: Lactose intolerance, fructose malabsorption, or sensitivity to certain food components can lead to similar gastrointestinal symptoms, including frequent bowel movements and abdominal discomfort after eating.

Colorectal Cancer: Although less likely in the absence of alarm symptoms like blood in the stool, weight loss, or a significant change in bowel habits in older adults, colorectal cancer can sometimes present with diarrhea or increased frequency of bowel movements. It's crucial to not miss this diagnosis, especially in individuals over 50 or those with a family history.
Thyroid Disorders: Hyperthyroidism can cause increased bowel movements, weight loss, and abdominal symptoms. While not directly related to the gastrointestinal system, thyroid function tests are often part of a comprehensive diagnostic workup for unexplained bowel changes.
Gastrointestinal Infections Requiring Specific Treatment: Certain infections like Giardiasis or Clostridioides difficile (C. diff) infection can cause chronic diarrhea and require specific antimicrobial treatment. Missing these diagnoses could lead to prolonged illness and potential complications.

Microscopic Colitis: This condition involves inflammation of the colon lining that can only be seen with a microscope. It often presents with chronic, watery diarrhea, which could fit the patient's symptoms.
Bile Acid Diarrhea: This condition, characterized by an excess of bile acids entering the colon, can cause chronic diarrhea. It might be considered if other diagnoses are ruled out and the patient's symptoms persist.
Short Bowel Syndrome: Although typically associated with a history of significant bowel resection, this condition can lead to chronic diarrhea due to the reduced absorptive capacity of the bowel. It would be an unlikely diagnosis without such a history but could be considered in complex cases.